Motor vehicle bodies are conventionally assembled from stamped sheet metal component parts which must be held precisely in three dimensional space relative to each other while welds are applied to join the panels into an integral body structure. For example, the body structure may be a subassembly such as an underbody, a wheel house subassembly, a floor pan or a body side ring.
It is accordingly well known to provide a rigid rectangular fixture frame, also known as a gate, a pallet, or carrier, which carries a plurality of clamping fixtures for clamping and locating the various component parts in the precise required relationship in readiness for the application of welds.
In particular it is known to loosely assemble a plurality of such component parts via interlocking tabs. The loosely assembled components are then conveyed into a body framing and welding station in which various fixtures clamp and precisely locate the component parts for welding. It is well known to mount such fixtures on a gate or frame and to move such a gate away from the body after the application of sufficient welds to tack the components together, so that the robotic welders are given unrestricted access to apply a large number of re-spot welds to the vehicle body.
It is also well known to assemble vehicle bodies of varied styles, for example, a coupe, a sedan, station wagon, etc. on the same body assembly system. Accordingly, the prior art has taught the provision of a gate or frame corresponding to each of the body styles and carrying the particular fixtures for that body style. Various apparatus, such as shuttles, conveyors, lift and carry mechanism, turn tables, and automatic guided vehicles have been employed to remove one gate from the welding station and then move the appropriate gate or frame into the framing and welding station for enabling the welding of the particular body style entering the body framing and welding station.
A disadvantage of the aforedescribed prior art body assembly system is that the storage and handling of a plurality of gates requires substantial floor space and handling apparatus and may adversely impact the cycle time for the body assembly system.
It would be desirable to provide a body assembly system having improved flexibility for the welding of a large variety of different styles of vehicle bodies and body components.